JP5998662B2 - Cooling structure for vehicle inverter - Google Patents

Description

  The present invention relates to a cooling structure for a vehicle inverter.

  Conventionally, a vehicle is known that is driven by an inverter via a generator by an internal combustion engine (see, for example, Patent Document 1).

  In this type of vehicle, a large current corresponding to a digit of several hundred Arms is generally allowed to flow inside the inverter, and it is necessary to forcibly cool the inverter.

  And in above-mentioned patent document 1, the improvement of the cooling efficiency of an inverter is aimed at by providing the cooling circuit according to the allowable temperature of each electrical machinery component inside an inverter.

JP-A 61-284944

  However, in the above-described prior art, the cost increases because a separate cooling circuit is provided according to the allowable temperature of each electrical component inside the inverter.

  Therefore, an object of the present invention is to obtain a cooling structure for a vehicle inverter that can reduce the cost.

The present invention is a cooling structure for a vehicle inverter that cools the vehicle inverter in a vehicle having a motor driven by the vehicle inverter as a drive source. The vehicle includes a transmission, and heat generating components of the vehicle inverter are immersed in transmission oil used for lubricating the transmission, and the transmission oil is a transmission for cooling the transmission oil. Circulating in an oil cooling circuit, the vehicle inverter is disposed in the transmission oil cooling circuit, the motor is disposed downstream of the vehicle inverter in the transmission oil cooling circuit, and the motor is disposed in the transmission. And the vehicle inverter is arranged above the transmission, and the transmission oil circulates in the transmission oil cooling circuit. In any state in a state in which no state and circulation, is characterized in that heat-generating components of the inverter power the vehicle is submerged oil at all times.

  According to the present invention, transmission oil used for transmission lubrication is used as a cooling medium for heat-generating parts of a vehicle inverter. Then, the heat generating component of the vehicle inverter is cooled by immersing the heat generating component of the vehicle inverter in the transmission oil. Therefore, it is not necessary to use a new cooling medium for cooling the heat generating components of the vehicle inverter, and it is not necessary to provide a new cooling circuit. As a result, it is possible to obtain a vehicle inverter cooling structure capable of reducing the cost.

It is a figure which shows typically the cooling circuit of the inverter for vehicles concerning one Embodiment of this invention. It is sectional drawing which shows typically the arrangement | positioning state of the inverter for vehicles concerning one Embodiment of this invention. It is a graph which compares and shows the temperature change of the inverter for vehicles by a plurality of cooling methods.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a hybrid vehicle capable of traveling by generating a driving force of the vehicle with the output of at least one of an internal combustion engine and a motor will be exemplified.

  The hybrid vehicle (vehicle) according to the present embodiment has an internal combustion engine (not shown) and a motor 70 driven by an inverter (vehicle inverter) 50 as drive sources. The hybrid vehicle (vehicle) can travel by generating a driving force with the output of at least one of an internal combustion engine (not shown) and the motor 70.

  In the present embodiment, the hybrid vehicle (vehicle) includes a transmission 60 having a gear train 61 that transmits power.

  Transmission oil 90 is used to lubricate the gear train 61 in the transmission 60.

  In this embodiment, the transmission oil 90 circulates in the transmission oil cooling circuit 10, and the gear train 61 is lubricated by introducing the cooled transmission oil 90 into the transmission 60.

  As shown in FIG. 1, the transmission oil cooling circuit 10 includes a storage unit 80 that stores the transmission oil 90, and the transmission oil 90 stored in the storage unit 80 is circulated by being pumped up by the pump 20. Then, the transmission oil 90 pumped up by the pump 20 passes through the filter 30 so that dust and the like in the transmission oil 90 are removed. And the transmission oil 90 from which dust etc. were removed passes through the cooler 40, and heat exchange is performed and it is cooled. The cooled transmission oil 90 is introduced into the transmission 60 and the gear train 61 is lubricated. Thereafter, the transmission oil 90 that has lubricated the gear train 61 is stored in the storage unit 80. The storage unit 80 may be provided outside the transmission 60 or may be provided inside the transmission 60.

  On the other hand, the inverter (vehicle inverter) 50 includes a large-capacity capacitor 52 and a power module 53.

  In this embodiment, the inverter (vehicle inverter) 50 is configured by providing the electronic substrate 51 on which the large-capacitance capacitor 52 and the power module 53 are mounted in the housing 50 a of the inverter (vehicle inverter) 50.

  A large current corresponding to the order of several hundred Arms flows through the large-capacitance capacitor 52 and the power module 53. When a large current is passed through the large-capacity capacitor 52 and the power module 53, the large-capacity capacitor 52, the power module 53, and the electronic substrate 51 on which these are mounted generate heat. In other words, in the present embodiment, the large-capacitance capacitor 52, the power module 53, and the electronic board 51 correspond to the heat generating components of the inverter (vehicle inverter) 50.

  Thus, it is necessary to forcibly cool the heat-generating component that generates heat by flowing a large current.

  Here, in this embodiment, the transmission oil 90 used for lubricating the gear train 61 of the transmission 60 is used as a cooling medium for the heat generating components of the inverter (vehicle inverter) 50.

  Specifically, an inverter (vehicle inverter) 50 is disposed in the transmission oil cooling circuit 10 and the heat generating components are cooled by the transmission oil 90 circulating in the circuit.

  In the present embodiment, as shown in FIG. 2, the inverter (vehicle inverter) 50 is disposed on the downstream side of the cooler 40 of the transmission oil cooling circuit 10 and on the upstream side of the transmission 60. A communication hole 54 communicating with the inside of the housing 50a is formed in the housing 50a of the inverter (vehicle inverter) 50, and the transmission oil 90 is introduced into the housing 50a from the communication hole 54.

  At this time, as shown in FIG. 2, heat generating components of the inverter (vehicle inverter) 50, that is, the entire large-capacity capacitor 52, power module 53, and electronic board 51 are completely immersed in the transmission oil 90. Yes.

  That is, the heat generating component of the inverter (vehicle inverter) 50 is always immersed in the oil regardless of whether the transmission oil 90 is circulating in the transmission oil cooling circuit 10 or not. ing. In this manner, the heat generating component is cooled by causing the heat generating component to be in an oil immersed state filled with omnidirectional oil.

  In the present embodiment, as shown in FIG. 2, a substantially L-shaped rib 50b is provided inside the housing 50a, and the electronic substrate 51 is placed on the rib 50b. Thus, by placing the electronic substrate 51 on the substantially L-shaped rib 50b, the back side of the electronic substrate 51 can be cooled by the transmission oil 90, and the cooling efficiency of the heat generating components can be further increased. it can. Furthermore, by providing the communication holes 50c in the ribs 50b, the transmission oil 90 on the back surface side of the electronic substrate 51 is prevented from staying, and the cooling efficiency of the heat generating components can be further increased.

  In this embodiment, the motor 70 is arranged in the transmission oil cooling circuit 10, and the transmission oil 90 is circulated in the order of the inverter (vehicle inverter) 50, the motor 70, and the gear train 61.

  Specifically, the motor 70 is arranged inside the transmission 60, and the transmission oil 90 that has passed through the inside of the inverter (vehicle inverter) 50 is introduced into the gear train 61 via the motor 70.

  An inverter (vehicle inverter) 50 is arranged on the upper part of the transmission 60.

  In the present embodiment, as shown in FIG. 2, a step 50 e corresponding to the step 60 c formed on the housing 60 a of the transmission 60 is formed on the housing 50 a of the inverter (vehicle inverter) 50. Then, the inverter (vehicle inverter) 50 is arranged on the upper portion of the transmission 60 so that the stepped portion 50e overlaps the stepped portion 60c. Further, the communication hole 50d formed in the housing 50a of the inverter (vehicle inverter) 50 and the communication hole 60b formed in the lower stage of the step portion 60c are communicated with each other. Thus, the communication oil 50 in the housing 50a can be introduced into the housing 60a of the transmission 60 by communicating the communication hole 50d and the communication hole 60b. In the present embodiment, the communication hole 50d and the communication hole 60b are communicated with each other at the lower stage of the step portion 60c. For this reason, the pressure of the transmission oil 90 in the portion where the communication hole 50d and the communication hole 60b are formed can be increased, and the transmission oil 90 can be introduced into the housing 60a of the transmission 60 more smoothly.

  As described above, in this embodiment, the transmission oil 90 used for lubricating the transmission 60 is used as a cooling medium for the heat generating components of the inverter (vehicle inverter) 50. That is, the large-capacity capacitor 52, the power module 53, and the electronic substrate 51 are cooled by the transmission oil 90.

  Specifically, an inverter (vehicle inverter) 50 is arranged in the transmission oil cooling circuit 10, and the heat generating components are cooled by the cooled transmission oil 90.

  Furthermore, the heat generating component of the inverter (vehicle inverter) 50 is cooled by submerging the heat generating component of the inverter (vehicle inverter) 50 in the transmission oil 90.

  Therefore, it is not necessary to use a new cooling medium for cooling the heat generating components of the inverter (vehicle inverter) 50, and it is not necessary to provide a new cooling circuit. That is, by using the transmission oil 90 used for lubrication of the existing transmission 60 for cooling the heat generating components of the inverter (vehicle inverter) 50, a cheaper cooling structure of the inverter (vehicle inverter) 50 can be obtained. it can.

  By the way, as a cooling method of the inverter (vehicle inverter) 50, in addition to the above-described method of immersing the heat-generating component in the transmission oil 90, for example, a cooling method using indirect cooling water or a method of cooling by immersing in cooling water. and so on.

  As shown in FIG. 3, using any of the above methods, it is possible to maintain the element part (the heat generating part in the present embodiment) below the thermal limit temperature (a in FIG. 3). In the case of the method of indirectly cooling the heat-generating parts using the transmission oil 90, the heat-generating parts cannot be cooled completely because the heat capacity is only 1/3 that of the cooling water, and the element parts (heat-generating parts) are limited to the heat limit. It cannot be maintained below the temperature.

  Here, referring to FIG. 3, in the cooling with the indirect cooling water, the difference (ΔT) in the temperature change of the component parts (heat generating parts) is relatively large (see b in FIG. 3). Thus, when the temperature change difference ΔT increases, the thermal degradation of the component part (heat-generating component) is accelerated, and the life of the component component (heat-generating component) is shortened.

  On the other hand, in the method of submerging the element part (heat generating part) in the transmission oil 90 shown in the present embodiment, the temperature change difference (ΔT) of the element part (heat generating part) is relatively small (FIG. 3). C)). Therefore, it is possible to suppress the thermal deterioration of the element part (heat generating part), and to extend the life of the element part (heat generating part).

  In addition, in the case of cooling by submerging the element part (heat generating part) in the cooling water, the difference in temperature change (ΔT) of the element part (heat generating part) is relatively small, and the element part (heat generating part) Can be maintained at a lower temperature (see d in FIG. 3). However, in order to submerge the element part (heat generating part) in the cooling water, it is necessary to ensure the insulation of the element part (heat generating part), which increases the cost. In this regard, in the method in which the element part (heat generating part) is immersed in the transmission oil 90, it is not necessary to ensure the insulation of the element part (heat generating part). Therefore, there is an advantage that it is possible to cool the element part (heat generating part) and to obtain a configuration that can extend the life of the element part (heat generating part) at a lower cost.

  Further, according to the present embodiment, the motor 70 is disposed in the transmission oil cooling circuit 10, and the motor 70 is disposed on the downstream side of the inverter (vehicle inverter) 50.

  That is, in the inverter (vehicle inverter) 50, the transmission oil 90 used for cooling the large capacity capacitor 52 and the power module 53 is used for cooling the motor 70, and finally the gear train 61 of the transmission 60 is lubricated. And used for cooling. As a result, the cooling medium for the entire hybrid system can be limited to the transmission oil 90 alone. Furthermore, since the cooling circuit for the inverter (vehicle inverter) 50 and the motor 70 can be configured in the vicinity of the transmission 60, the configuration of the cooling circuit can be simplified.

  Further, according to the present embodiment, the motor 70 is disposed inside the transmission 60, and the inverter (vehicle inverter) 50 is disposed above the transmission 60.

  As a result, a circulation circuit for circulating the transmission oil 90 used for cooling the inverter (vehicle inverter) 50 for cooling the motor 70 can be shortened. Therefore, the transmission oil cooling circuit 10 including the inverter (vehicle inverter) 50 and the motor 70 cooling system can be made more compact.

  As mentioned above, although the cooling structure of the inverter for vehicles concerning the present invention was explained taking the above-mentioned embodiment as an example, the present invention is not limited to the above-mentioned embodiment, and other embodiments are within the scope not departing from the gist of the present invention. Various types can be adopted.

  For example, in the said embodiment, the hybrid vehicle was illustrated as a vehicle. However, the present invention is not limited to a hybrid vehicle, and the present invention can be applied to any vehicle including a vehicle inverter and a transmission.

  In addition, transmissions, vehicle inverters, and other detailed specifications (shape, size, layout, etc.) can be changed as appropriate.

10 Transmission oil cooling circuit 50 Inverter (vehicle inverter)
51 Electronic board (heat-generating component)
52 Large-capacity capacitors (heat generating parts)
53 Power module (heat-generating component)
60 Transmission 70 Motor 90 Transmission oil

Claims (1)

A vehicle inverter cooling structure for cooling the vehicle inverter in a vehicle having a motor driven by the vehicle inverter as a drive source,
The vehicle includes a transmission,
The heat generating component of the vehicle inverter is immersed in transmission oil used for lubricating the transmission ,
The transmission oil circulates in a transmission oil cooling circuit for cooling the transmission oil,
The vehicle inverter is arranged in the transmission oil cooling circuit, and the motor is arranged downstream of the vehicle inverter in the transmission oil cooling circuit,
The motor is disposed inside the transmission, and the vehicle inverter is disposed at the top of the transmission.
The vehicle inverter is characterized in that the heat generating component of the vehicle inverter is always immersed in the oil regardless of whether the transmission oil is circulating in the transmission oil cooling circuit or not . Inverter cooling structure.

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